Transmission mechanism



March 4, 1952 K. K. PROBST TRANSMISSION MECHANISM Filed March 27, 1947 Patented Mar. 4, 1952 UNITED STATES PATsNT GFF-ICE '2,588,161 TRANS-MISSION M-EcHirNisM Karl K. AProbst, Lansing, Mich. Application Marc`l'1'27, 1947*, Serial No. 7373487 12 claims. (Ci. i4-7&5)

i This invention relates to variable speed transmissions vfor motor vehicles and lmore particularly to such transmissions employing a planetary gear system.

It .is an object of this linvention to `provide 'an' j Aimproved type variable speed transmission which has relatively few `gears for the variable speeds 4it Y produces in comparison `with those presently `employed.

It is a further object of this invention to provide a variable speed transmission capable `of providing four forward `speeds fand one reverse speed .and which employs a planetary .gear system .of relatively Afew .gears to produce this result;

-It is a further .object of this invention to provide a variable speed transmission .of relatively small size which will be enicient in .operation and simple ,to construct.

These and other objects .of my invention will lbecome apparent from the following `detailed .de-

scription taken'in conjunction with the accomi .panying drawings, in which:

.Figure `1 is .a cross-sectional View ,of the transmission of this invention;

Fig. 2 is va cross-.Sectional View of the planetary:

system ,of transmission taken along the line .2-2

of Fel- Referring to the .cl-rawing, the rear end of `an engine crankshaft is illustrated at ill and as being provided with the usual mounting iiangge upon which a iiywheel is ismount'ed in concentric relation with respect thereto and secured thereto by means of screws .|6. The ii-,yWheel 4I4 isfof *the conventional type provided with' Va rearwardly projecting rim [lf3 .providiifi'gVr ac ncehtric cylindrical recess or pocket 20 Vtlfierein bounded at .itsl forward 01" left-hand ,end bya wall 22 prpendicular to the axis of rotation of the crankshaft I 0. A radially inwardly projecting abutment plate orring 24 is secured to the rear face ofthe Vflywheel rim vl 8 in concentric relation with respect thereto `by means of screws "2 6, the forward or left-'hand face of the abutment rijg y24 being perpendicular to the axis' of the' crank- -shaft I0 and Vthereff'ire parallel with the face 22 -of the `flywheel I4.

Received in the pocket 20 in concentric rela- -tion with respect thereto is .a pressure .plate .or

- :annular ring 28 which will be .observed to .be .of

less thickness than vthe axial depth ofthe pocket 12e. This pressure plate .or .ring v2t is .mounted et its 'periphery by .a plurality .of preferably equally .singularly Stated bars. suitably .rxesl thereto .in :parallelrelaiion with .respect i0 -the. axi.s..fs f .the .crankshaft .l- Each .bar 3.0 :is axially .slid- .openings `3l in .each ofthe bars.

ably received in an opening 32 Yin the flywheel i4 and an aligned opening34 in the plate .24, .the opening 32 in .the flywheel being extended into the rim I8 thereof as a radially inwardly opening groove in v.the recess 2i) which `exposes the -radially inner face of the bar .30 therein for anchorage to the pressure plate 128.

Positioned 'between the Vpressure plate 28 :and .the wall 22 .of .the flywheel t4 vis a conventional friction vclutch plate 35 having .oppositely disposed friction faces 36 and 31. The .clutch plate 35 Ais splined to a .shaft 3'8 concentric with the axis .of .the crankshaft .lli and icurnaled at its vforward end in a bearing 42 mounted in a .central aper- .tu-re in the rear .end .of the crankshaft. A second clutch plate 39 having .opposed friction faces .4B and 4| is .positioned between the pressure plate 28 and the abutment `ring 24 secured .to the rear face of the flywheel and is splined to a shaft 43 which is coaxial with and rotatably surlrounds the shaft 38. Shaft t3 is adapted .to `rotate independently .of shaft 38 when driven :by clutch plate 39. Upon movement of the 'bars 30 forwardly .or rearwardly the pressure plate 28 is moved forwardly for rearwardly so as .to .clamp one .of the clutch plates between yit and the flywheel, .depending 4on which way Vit is shifted.

The Vbars -30 are conventionally .operated :by shifting arms .ll4-, .pivotally supported by ears .44a which are xedly .connected to the plate 24 so that the arms 44 will rotate with .the .plate 24, and the arms are connected in radially ydirected The .opposite end of shifting arms 413 is .connected in a yoke .t5 of a *..hub unit .or .clutch .control .collar .4.5, .correspondingr somewhat to a .conventional clutch .throw-.out collar. This unit .4t is adapted .to be .shifted forwardly and rearwardly .by ,an Iarm ..41

which issecured to a .clutch .shifter shaft. 48....by

:means .of aset `screw 49. The shaft 423k is adapted .to be .operated .ina .Suitable or conyentioiial Yinailner so that .the .bars 3B may .be .moved DIM/ldly :or rearwardly .to .engage the pressure plete .28 with either of the clutch plates `3.5 Aand .3.9. A

Rearwardlyof :the .flywheel I4 a planetary eser ysystem is provided for furnishing vthe.Ziilfiells ,eut-

' 100.11@ type t0 prei/entera ,endthfrufst f .Sei-up.; from. torque. beine. transmitted -ihrelgh the gears. 'These Egears are carried by a carrier 51 which comprises two oppositely disposed end walls 59 and 6| between which three pins 63, one for rotatably supporting each gear extend, with one end of each pin mounted in end wall 6| and the other end shouldered and passing through and secured to the end wall 59 by means of a nut 65 threaded on one end of pin 63 to hold it flrmly in place. A staggered tooth herringbone gear 61 is also rotatably mounted on each pin 83 and each planetary gear has a, recess 10 in one end thereof in which a projecting cylindrical shank portion 69 of each gear 61 is received. Suitable means are provided for rigidly connecting each of the gears 61 to its respective planetary gear. The gears 61 mesh with a complementary gear 68 which is splined to the shaft 38 to provide a driving connection therebetween.

The planetary gears 5|, 53 and 55 mesh with gear teeth on the inner periphery of a ring gear 1|. An annular brake band 13 is positioned between the outer periphery of the ring gear 1| and the housing 14 for the clutch and transmission which surrounds the ring gear. It will be understood that this housing is of a moreor-less conventional type having a fianged forward end adapted to be secured to the rear end of the associated engine block so as to be supported thereby. The band 13 may be tightened to prevent rotation of the ring gear by any suitable means. In the drawings, as best shown in Fig. 2, the band 13 is illustrated as split and having its ends 15 bent outwardly. These end portions 15 have aligned apertures therethrough, through which a threaded bolt 16 passes. The head of the bolt 16 abuts the surface of one end portion and a cam element 11 is threaded onto the lower end of the bolt which projects through the other brake end portion 15. rI'he cam element 11 is actuated by a lever 18 which passes through an elongated aperture 19 in the transmission housing, and when the lever is moved downwardly it causes the band 13 to tighten around the ring gear and prevent its rotation. Any suitable conventional means may be provided for actuating the lever 18.

Positioned between the portion of the housing 14, which houses the planetary gear system, and the portion which houses the flywheel and clutch plates, is an annular wall or flange 8|, the inner periphery of which terminates in a forwardly extending sleeve portion 83 coaxial with the shaft 43 and forms a bearing therefor. The clutch control collar 46, previously described, is slidably mounted on the exterior of the stationary sleeve portion 83 and is movable either forwardly or rearwardly thereon.

The outer portion of the flange 8| is sealingly secured to the front face of an inwardly extending radial housing flange 85, by any suitable means. The inner periphery of the flange 8|, rearwardly of the sleeve portion 83, is recessed as at 81 to receive a conventional oil seal 89 therein which prevents lubricating oil for the planetary gear system from entering the forward portion of the transmission and clutch housing 14.

The inner periphery 90 of the end wall 6| of the carrier 51 is supported on a hub 9| of the ange 8|, and needle or other suitable bearings 93 are disposed between the hub and end wall inner periphery to allow rotation therebetween.

A ring or drum element or member 95, having a central aperture 91 therein is mounted on a cylindrical hub 99 formed on the outer end of the end wall 6|, and the drum element is rigidly secured to the end wall by any suitable means,

rsembled for repair purposes.

such as bolts, rivets, or the like. The drum member is concentric with and has its outer periphery disposed adjacent to the adjacent inner wall of the housing 14. A second brake band |00 is positioned between the housing 14 and the outer periphery of the drum member 95, and is similarly adapted, as is the brake band 13, to be tightened to prevent the rotation of drum member 95 and thus of the entire carrier 51. The ring gear 1| has a spider |0| secured to its rear face by means of bolts |02 and nuts |03. Surrounding the shaft 38 and secured to the rear face of the spider |0|, by means of rivets |05, is a conventional clutch jaw |01 of the dog type.

Rearwardly of the splined connection between the gear 68 and the shaft 38, a coaxial sleeve ||3 rotatably surrounds the shaft 38. This sleeve ||3 is secured to the end plate 59 of the carrier 51 by means of rivets ||4 thereby supporting the rear end of the carrier 51 on the shaft 38. The sleeve ||3, being rotatably mounted on the shaft 38, turns only when the end plate 59 of the carrier drives it. An outwardly facing clutch jaw ||5 of the dog type is formed on the rear end of sleeve ||3 and adapted for use as will be hereinafter described. Positioned adjacent the rear of the sleeve ||3 is a second sleeve ||1 which is splined to the shaft 38. This sleeve ||1 is likewise provided with an outwardly facing radial clutch jaw ||9 of the dog type. A third sleeve |2| is rotatably mounted on shaft 38 and has its front end abutting the rear of sleeve ||1. The outer periphery of this sleeve |2| is formed with longitudinal splines |23 thereon. Coaxial with the sleeves and slidably mounted thereon is a shiftable clutch control collar. Two sets of radially inwardly facing dog type clutch jaws |21 and |29 are provided on the inner periphery of the clutch collar |25 and are spaced at opposite ends thereof. On the outer periphery of the clutch collar |25, at the forward end thereof, is a third dog type clutch jaw |3| which faces outwardly and is adapted to engage the jaw |01 on the spider |0| when the clutch collar |25 is so shifted. Jaw |29 on collar |25 engages the splined portion |23 on sleeve |2| at all times. The jaw |21 is adapted to engage either the jaw ||9 on the sleeve ||1 or the jaw ||5 on sleeve ||3, depending on the position of the clutch collar |25.

The clutch collar |25 is provided with a yoke |33 on the outer periphery thereof into which a shifting arm |35 is tted. This shifting arm |35 is secured to the clutch shifter |36 and shifts the clutch collar |25 in the same way that the arm 41 shifted the clutch control collar 48, as previously described.

The clutch and transmission housing is divided into two parts, so that it may be easily disas- The forward housing portion 14 terminates adjacent the rear of the planetary gear system and a second housing portion |39 is sealingly secured thereto by any suitabl means. Rearwardly of clutch collar |25 the shaft 38 terminates at the rear of the transmission housing portion |39. The end of the shaft is supported by the sleeve |2| which extends through the rear of the housing where it is rotatably supported in a bearing |4| mounted in the housing. The sleeve |2| is connected to a stub shaft |43 by means of a nut |45 screwed on the end of the sleeve. The stub shaft |43 is rotatably supported in a universal joint |41 mounted in Aa nab member 44s attested to the rear Iof the transmission ihousing portion -l| 39.

'In operation, the transmission-illustrated 4in `the drawing willproduee tfour forward speeds and one -reverse speed. The forward speeds illustrated in the drawing comprise van emergency -low speed, a secondsp'eed a third speed, and 4a high speed, or direct drive, but it will readily be seen that the transmission could be 4constructed so as to employ only certain yof these forward l'speeds or any combination thereof.

When it is ldesired `=to `drive the vehicle at the emergency low speed, the clutch plate 39 is clamped between 1the valcminnent ring 24 of 'the flywheel I4 and the pressure plate 28 by shifting the pressure plate rearwardlyas.previouslyvdescribed The shaft 43 is then rotated, due to its connection with `the engine flywheel |14, which in turndrives the sungear 50 which Vis vfixedly mounted on the shaft-43. At thistime Ythe brake band 13 is tightened so -as to prevent vthe .ring @gear 1| from ro- =tating,1therebycausing the planetary gears 5 I, 53, and 55 and the entire `carrier `51 v.to planetate about the shaft 43. 'This causes rotation of the gears 61 mounted on the pivot-pins 63 .f the .car- -rier 51 which in turn mesh with 4the complementary gear -68 which issplined to the shaft 38. The clutch'collar |25 inthe meantime has been shifted forward so that clutch jaw |21 is :meshed lwith the jaw |I5 on the sleeve I |;3 -.which,is connected -to the carrier 'by rivets |4. The other jaw |29 is still in engagementwith` the splines of sleeve |24 and therefore .drives .the-sleeve |2| at the same rate that the sleeve ||3 is being driven. 'The sleeve |2| `in turn being vconnected to the final ldrive mechanism, i. e., stub shaft |43 and associated structure drivesy that-mechanism at the same speed. In the emergency low speed drive, illustra-tedin the drawing, and with gears proporrtioned as shown, there is Va reduction of speedbetween the .engine and the transmission final drive mechanism of vapproximately 45.4.

When the 4second `forward speed is desired, the

- clutch plate 39 is again engaged with the flywheel I4. Thefbrake band is tightenedaround the Aring `or drum member -95 to prevent itfromrotating and the clutch collar |25 is shifted so that its clutch VJaw |21 is engaged with the jaw I I9 of the sleeve ||1 and its other jaw V|29 is engaged lwith the splined portion |23 of the sleeve |2|. Once againl -the clutch plate 39 causes the shaft 43 to rota-te and therefore causes the sun gear 50 lto drive the planetary gears 53'and 55. As the brake band |00 has Vbeen tightened about the ring or drum member 95 thecarrier 51 cannot rotate. -This forces the planetary gears to rotate about their vown axis `and cause the gears 61, mounted on the pins 63 of the carrier 5l, to rotate and `drive the complementary gear 68 on the splined shaft 38. This causes the sleeve Awhich is splined to the shaft 38, .to rotate at the same speed. `Sleeve |2| 'being connected through the clutch collar |25 to the sleeve I|1 is likewise -rotatedanddrives the final drive mechanism at that speed, which in the embodiment herein -illustrated, and with gears `proportioned as shown, is reduced approximately 2.5 -times that of engine speed.

`In order -to obtainthe third forward speed, the clutch plate 39 -is again engaged with the flywheel |4 and .the brake `band 13 is clamped tightly Varound thering gear 1|,preventing"its rotation. `The clutch collar .|25 is in the same position as for second speed. As the brake band 13 prevents :the -ri-ng. geary 1| yfrom rotating, .once 4more the B planetary gears and the carrier are caused to planetate about the =shaftff43 and the gears 61 Yare mes'h'ed -with the complementary Agear 68--rotate the-shaft 30.- The ifotationfof .theshaft 38 causes 'the lSleeve I |11, which lis v-splined thereto to rotateand the sleeve :12| is driven, las Vdescribed .for second speed, vand udrives .the final vdrive i inechan'i'sm raft-'a speed reduction -of 1 approxinoately y1.957 times that ofthe engine :speed -lwith gears proportioned -as shown. u

When high .speed or :direct fdrive is desired, the pressure plate 28 is moved forwardly .to clamp -the .cl'utch Iplate 35 *between it -and the end v.wall 22 of the ily-wheel |4. The clutch plate 35 :then drives the shaft 38 which yin :turn :drivesstraight -throu-gh the transmissionfwithout. operating the planetary gear system. `The clutch .col-lar 125, which ispositionedthevsame as it was for tthe second and thirdspeeds, drives-fthefinal speed mechanism, as described, at the same speed as that v`of l.the engine.

When i-t .is `desired tozreverse the direct-ion of `rotation of the nalspeed mechanism,- thecluteh plate '39 is yonce more engaged with the `flywheel =|4. 'The brake band |00 tightened around the ring or drum member 95 -t'o prevent rotation of the carrier, and the-clutchl vrcol-lar |25 -is shifted forwardly so that the clutchjaw-IZT engages Iwith the iaw |01 on ,the spi-der '|0'|. Clutch fjafw 2-9 -is still lin contactwith the-splinesven the sleeve |2j| so as y-to drivev the lnal speed-mechanism. The shaft 43 drives the sun gear 50 which in turn causes the planetary gears to rotate about their own axes. This rotation is stil-l in the same -direction as that of theY shaft '43.' The planetary gears then oause'the ring Agear v1| to rotate in Vthe opposite direction from that of the shaft 43. The spider |0^| which isco'nnected tothe ring gear 1|,through thebolts |02, then isrrotated rin the same direction as the ring gear y'I I. As the clutch collar 25 has *its jaw l|21 in engagement with the jaw |01 of the'spider, the spider causes the sleeve `|2-I, and thus the -nal drive mechanism", to rotate :but in an opposite direction from that of the shaft 43 thereby reversing the direction of -rotation of the transmission lfinal drive mechanism from that'of vthe engine. Thespeed ratio between the engine land final drive' mechanism of this `reverse'dr'ive is equal to that of 'the emergency `low 'forward speed of theengine.

It is always" possible nby" removing certain; of the` clutch jaws on either the clutch collar '|25 or on its complementarygengaging members to eliminate any of the speeds of the'Y transmission without affectingthe remainder' of the drive speeds. For example, by eliminating the clutch jaw |15 on sleeve |13, it will readily be seen that the emergencylo'w forward speed of the transmission `will be eliminated but will leave the remainder of the forward speeds and the reversespeed unaie'cted. Likewise, if the clutch vjaw" ||9 on the sleeve H1 were removed, the second Vforward speed ofthe transmission would be eliminated without affecting the remainder of the speeds. Thus, it will readilyappear that vthe transmission may be constructed with any combination of the speeds `shown inthe embodiment of the drawings. I

While Iv lhave described one particular embodiment of my inventiomit is to be understood that =I do not -wish to be,restrictedthereto. and that I intend to cover ,all modifications thereof which would `.be apparent to'oneskilled inthe art fand which come within the spirit andscope .of the :appended claims'i.

I claim:

l. A- variable speed transmission comprising Y a driving member, a pair of coaxial driven shafts, clutchplates mounted on each of said shafts engageable with said driving member, a nal drivemechanism mounted on a rst of said driven shafts a planetary gear system comprising a sun gear mounted on the second of said driven shafts, planetary gears driven by said sun gear and a ring gear driven by said planetary gears, a carrier having said planetary gears rotatably mounted thereon and a second gear coaxial with and connected to each of said planetary gears, means. operable to hold said carrier against rotationfto cause said gears to rotate about their own axes, means operable to hold said ring gear against rotation to cause rotation of said carrier and planetation of the gears about the axis of said driven shafts, a gear mounted on the first driven shaft drivable by said second gears mounted on said carrier, a sleeve coaxial with said Adriven shafts, a plurality of clutch jaws on said sleeve, one set of which is connected to said final drive mechanism at all times, a jaw connected to said carrier engageable by one jaw on said sleeve` for all other forward speeds, a jaw connected to.

said'ring gear and engageable with still another jaw on said sleeve for reverse driving of said final drive mechanism.

2. A variable speed transmission comprising a firsthollow shaft and a second shaft of substantially greater length rotatable within the first shaftand having clutch means beyond the end of the first shaft, means at one end of the transmission for selectively driving either of said shafts, planet gears, means drivably connecting the planet gears to the first shaft at an end thereof, gears connected to the planet gears to move therewith, a gear secured to the second shaft beyond the end of the first shaft and driven by at least one of said gears, a carrier drivably connected to the planet gears to be rotated thereby and having a hub with clutch means rotatably mounted on the second shaft, a ring gear driven by the planet gears having a hub with clutch means rotatably mounted on the second shaft, means for preventing rotation of the ring gear, means for preventing rotation of the carrier, an axially movable clutch member mounted on the second shaft and selectively engageable with either of the clutch means, and means for operf atively connecting the clutch member to mechanismto be driven through the transmission.

3. A variable speed transmission comprising a rst tubular drive shaft, a second drive shaft rotatably extending through the first shaft, first clutch means at the power-input end of the transmission selectively operative with the end portions of the shafts to connect either to a power source, a planetary gear unit drivably mounted upon the first shaft at the end remote from said clutch means, said unit including a rotary ring gear member and planet gears, said planet gears having a driving connection with the second shaft, said unit including a rotary carrier member drivably connected to said planet vgears to rotate due to revolution of the planet gears about the first shaft, means for holding the ring gearmember against rotation, means for holding the carrier member against rotation, the second shaft and at least one of the two members having axially fixed clutch means beyond the end of the first shaft, and axially movable clutch means at the power output end of the transmission selectively engageable with the respective axially fixed means, said movable clutch means providing a power take off for connection to a mechanism to be driven through the transmission.

4. The invention as claimed in claim 3 wherein the movable clutch means comprisesv a com mon clutch member.

5. The invention as claimed in claim 3 wherein the respective axially fixed clutch means are axially spaced and the movable clutch means comprises an axially movable common rotary clutch member slidably disposed on the second shaft.

6. In a variable speed transmission the combination of a planetary gear unit including a sun gear and planet gears, a first drive shaft for rotating the sun gear and thus the planet gears, a rotary carrier, said planet gears being rotatably mounted on the carrier whereby planetary movement of the gears causes rotation of the carrier about the axis of the first shaft, first means for holding the carrier against rotation thus causing the planet gears to rotate about their own axes, an internal rotary ring gear engaging and surrounding the planet gears and rotated thereby about the axis of the first shaft, second means for holding the ring gear against rotation thus causing the gears and the carrier to have planetary motion about the axis of the first shaft, coaxial gears affixed to the planet gears to `have identical rotary and planetary movement therewith, a shaft gear engaged and driven by the coaxial gears, and a second shaft secured to and driven by the shaft gear, said first shaft being hollow and said second shaft rotatably extending therethrough to beyond the planetary gear unit, means on said second shaft beyond said unit whereby said shaft may receive torque independently of the first shaft.

'7. In a variable speed transmission, a rotary shaft, a first rotary member disposed on the shaft and having a hub portion with a radial clutch ear thereon, a second rotary member disposed on the shaft and having a hub portion with an internal clutch recess therein spaced axially from the clutch ear, said shaft having a radial clutch ear on the other side of the first ear from the clutch recess, a rotary sleeve on the shaft beyond the shaft clutch ear, an axially movable rotary clutch sleeve rotatively connected to the rotary sleeve, said clutch sleeve having an internal clutch surface engageable with said clutch ears and an external clutch surface engageable with the internal clutch recess whereby rotation is transmitted from the shaft and members to the sleeves, and means for imparting predetermined rotation to each of the members and to the shaft.

In a variable speed transmission, the combination of a hollow shaft, a planetary gear unit including a sun gear, planet gears, and a ring gear, said unit being drivably mounted upon the inner end of the hollow shaft, a second shaft extending through the hollow shaft, gear means on the second shaft adjacent the inner end of the hollow shaft, rst means operatively connecting the planet gears to the gear means whereby rotation of the planet gears rotates the gear means, a brake member rotatably secured to the planet gears for rotation about the axis of the hollow shaft, second means for fixing the brake member and therefore the planet gears against rotation about the axis of the hollow shaft, braking means for fixing the ring gear against rotation, a power takeoff member rotatably mounted on the second shaft and having radial force transmitting surfaces, third means including radial force transmitting surfaces whereby the second shaft may be operatively connected to the power takeoff member, fourth means including radial force transmitting surfaces whereby rotation of the planet gears may be transmitted to the power takeoff member, fifth means including radial force transmitting surfaces whereby the ring gear may be operatively connected to the power takeof member said radial force transmitting surfaces being axially spaced,]sixth means for selectively providing a drive connection between each of the third, fourth, andA fifth means and the power takeoff member comprising an axially movable member having radial force transmitting surfaces in engagement with the surfaces on the power takeoff member and having additional radial force transmitting surfaces selectively engageable with the surfaces of the third, fourth, and fifth means, and means for independently driving either of the shafts.

9. The invention as claimed in claim 8 wherein the first means comprises gears coaxially secured to the planet gears for planetary movements therewith.

10. In a variable speed transmission, the combination of a hollow shaft, a planetary gear unit including a sun gear, planet gears, and a ring gear, said unit being driven by the hollow shaft and mounted upon the end thereof adjacent the output side of the transmission, a second shaft rotatably extending through the hollow shaft, gear means aixed to the second shaft adjacent the end of the hollow shaft, gears coaxially secured to the planet gears for planetation therewith and disposed on the output side of the planet gears, said gears having a driving engagement with the gear means, a rotary braking member on the input side of the planet gears operatively secured to the gears for rotation about the axis of the hollow shaft, means for fixing the braking member against rotation, means for selectively preventing rotation of the ring gear, a first hub rotatably disposed on the second shaft adjacent the gear means and on the output side thereof, means drivably connecting the hub to the planet gears for rotation about the axis of the second shaft, a second hub rotatably disposed on the first hub and having an internal annular clutch recess, means drivably connecting the second hub to the ring gear for rotation about the axis of the second shaft. a first radial clutch ear on the first hub on the output side of the clutch recess, a second radial clutch ear drivably secured to the second shaft on the output side of the first ear, a power takeoff sleeve rotatably mounted on the second shaft on the output side of the ears, and a clutch sleeve rotatively secured to the takeoff 6 sleeve but slidable thereon and on the second shaft, said clutch sleeve having means for driven engagement with the clutch recess and means for driven engagement with the first and second radial clutch ears, and means for axially shifting the clutch sleeve to selectively operatively connect the first and second hubs and the second radial ear to the takeoff sleeve.

1l. A variable speed transmission comprising a rst drive shaft, a second drive shaft, means for selectively driving either of the shafts, a planetary gear unit driven by the first shaft including a rotary ring gear member. a gear secured on the second shaft and driven by the unit, said unit including planet gears and a carrier member connected to the planet gears to revolve therewith, means for holding the ring gear against rotation, means for holding the carrier member against rotation, the second shaft and the two members having axially fixed clutch means, and movable clutch means selectively operatively engageable with the respective fixed clutch means, said clutch means providing a power take-off for connectionto a mechanism to be driven through the transmission, said fixed clutch means being axially spaced from each other and said movable clutch means comprising an axially movable common clutch sleeve surrounding an end portion of the second shaft.

12. In a variable speed transmission, the combination of a first drive shaft, a second drive shaft, means for selectively driving either of said shafts, a pair of sun gears one secured on each of said shafts, a planet gear having one portion in driven engagement with the sun gear on the first drive shaft and another portion in driving engagement with the sun gear on the second drive shaft, a rotary ring gear in driven engagement with the planet gear, a rotary carrier drivably connected to the planet gear, means for selectively preventing rotation of the ring gear, means for selectively preventing rotation of the carrier, and power take-off means operatively connectible to the second shaft. the ring gear, and the carrier.

KARL K. PROBST.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 686,786 Upton Nov. 19, 1901 817,908 Folberth Apr. 17, 1906 1,901,193 Salerni Mar. 14, 1933 1,978,416 Dodge Oct. 30, 1934 2,045,613 Padgett June 30, 1936 2,078,466 Stauffer Apr. 27, 1937 2,102,634 Lysholm Dec. 21, 1937 2,277,214' Dodge Mar. 24, 1942 2,372,817 Dodge Apr. 3, 1945 2,398,208 Chilton Apr. 9, 1946 2,406,225 Kelbel Aug. 20, 1946 FOREIGN PATENTS Number Country Date 5,835 Great Britain Mar. 11, 48.019 France June 29, 1937 146,668 Great Britain May 1, 1919 809,102 f France Dec. 3, 1938 

